From baseball games to backyard cookouts, beer is a summertime staple in the U.S. But you might be surprised to find how much time, effort and money is involved in growing just one brew ingredient: hops.

Easily growing up to 20 feet tall, hop plants require labor-intensive training, trellising, pruning and harvesting, which can also call for specialized equipment. And when hops receive too much heat, or don’t obtain enough light, greenhouse hop growers turn to shade curtains or supplemental lighting — more added costs.

But demand for hops and starter hop plants is prompting some craft brewers and hobby home brewers to purchase products from greenhouse producers.

Jon Vanden Heuvel, vice president of Sandy Ridge Farms in Zeeland, Michigan, supplies starter hop plants to finished growers, who are in turn, growing and harvesting hop cones for brewing. As a greenhouse manager and former home brewer, he ventured into growing hops around 2006 during a hop shortage in the primary hop-producing states of Washington, Oregon and Idaho.

“That’s when the hop production industry in Michigan and in the Midwest started to take off, because the Pacific Northwest wasn’t producing to the demand at the time,” he says. “It was kind of right place, right time. I learned that I was better at propagating plants than I was at growing them in the field, so we moved it into the greenhouse and started to market starter plants to the farms that were going in in Michigan.”

Now Vanden Heuvel ships an estimated 100,000 plants a year — sometimes more — regionally, nationally and internationally to finished growers. In some cases, he can trace hops harvested from his plants, once they fully grow and are harvested by one of his customers, to specific craft breweries such as West Michigan’s Bell’s, Founders and New Holland.

Sandy Ridge Farms has 110,000 square feet of greenhouse production space, including about 20,000 square feet for hops production and 5,000 for hydroponic lettuce. Ornamental perennials such as hostas, daylilies and clematis make up the rest of the greenhouse’s production.

Vanden Heuvel grows his 3- to 6-inch-tall hop plants in the greenhouse, scattered throughout the rest of his production. He controls the environment similarly to his ornamental perennial production.

A few years ago, the company transitioned from growing annuals to perennials. When they were growing annuals alongside hops, they ran into production issues with heat.

“Hops are a plant that will grow a foot a day, so the cooler you can grow it, the more controlled it is,” Vanden Heuvel says.

Sandy Ridge Farms propagates its starter plants using green cuttings from stock hop plants. The operation has had field-ready plants in eight to 12 weeks, but usually allows about four months to produce them.

“Ideally, we’re doing the cutting and the sticking in the summer, and then the guys are planting them in the spring,” Vanden Heuvel says. “That gives them that winter to vernalize in the greenhouse.”

Hop production techniques

Sandy Ridge Farms acquires its stock plants from the USDA’s National Clean Plant Network out of Prosser, Washington, and follows strict sanitation protocols. The operation propagates roughly 50 varieties, including USDA’s new Triumph variety, which it will begin selling in July.

“Starting seed with hops is incredibly rare, and it’s also rather difficult,” says Brian J. Pearson, assistant professor of environmental horticulture at the University of Florida. “Getting them from rhizome has been the traditional way of getting it.”

But he tells growers who have an interest in producing hops to consider tissue culture propagation so they can bring in a disease- and virus-free product, and have consistent parentage.

As with other crops, it takes effort to control viruses, pests and diseases in hop production, Vanden Heuvel says. Hops are susceptible to powdery mildew and downy mildew, as well as thrips and spider mites.

“It has to be treated as an edible, so the spray routines — the chemicals that [you] are allowed to use in the greenhouse — is greatly reduced,” he says. “They’re on a spray rotation similar to impatiens for impatiens downy mildew, so we’re spraying very regularly. But the chemical base to rotate through is not nearly as broad. That presents challenges in itself.”

Greg Stelzer, co-founder of finished hydroponic grower 24 Hour Hops, says another production consideration is that hops require vernalization to improve their plant vigor and root hardiness, and produce higher yields of better-quality cones than first-year plants.

24 Hour Hops has been growing hops in a 3,000-square-foot greenhouse leased from the University of Arizona since 2017, but recently halted production as it looks for investors.

To vernalize its hop plants, 24 Hour Hops chopped the crops down to the root crowns and placed those in refrigerators to simulate winter conditions.

“With that said, we did do some second grows,” Stelzer says. “We chopped them down and then just let them grow again to do some experimentation. They did pretty well. We just figured that since Mother Nature tried it, we’d try it both ways.”

24 Hour Hops, along with the few other finished greenhouse hop growers, often specialize in fresh hops. While most hops are dried right after picking, fresh or “wet” hops go straight into the beer-making process.

The operation carved out a niche selling its fresh hops to home brewers, but it also sold to some craft brewery clients such as SunUp in Phoenix and Dubina in Glendale, Arizona.

24 Hour Hops grew in Dutch buckets, trellising the climbing plant stems called bines. They leaned and lowered the bines, similarly to the way a grower of indeterminate tomatoes would treat vines in the same production system. They also used LEDs to manipulate the photoperiod and shade cloth to reduce the amount of brutal Arizona heat entering the greenhouse.

While Stelzer doesn’t come from a horticulture background (he worked in the tech sector) he says he would imagine experienced growers could catch on to producing hops pretty quickly.

“I think this is one of those plants that wants to grow,” he says.

Still, growers must consider the time it takes for hop plants to mature. Sandy Ridge aims to save its finished grower customers time by allowing them to get a full yield of hop cones a year sooner than if they grew from rhizomes, Vanden Heuvel says. The reduction is from three to four years, to two to three.

At the University of Florida’s Mid-Florida Research & Education Center in Apopka, Florida, Pearson and his colleagues have grown hops in a semi-enclosed greenhouse, then in a heated and cooled greenhouse with a polycarbonate roof, using deep water culture hydroponics.

“We ended up doing a post on social media showing a hop harvest in January,” Pearson says. “We got quite a few positive feedbacks from folks in the Pacific Northwest, thinking how cool it was that we had some fresh hops available. And I see that ... here we have fresh hops available when nobody else in the U.S. has that.”

Challenges of greenhouse hops production

Despite the potential for greenhouse growers to offer hops year-round, Pearson says many questions remain about growing hops in a greenhouse and its feasibility for profitable commercial production.

“There’s pros and cons to every production system. And yes, greenhouses have the con of oftentimes being more expensive than a field because you’re paying for electricity; you’re paying for water; you’re paying for light. But the pro of it is you can control your environment to a higher degree.”

Jaki Brophy is communications director at Hop Growers of America, a nonprofit trade organization based out of the high hop-producing city of Yakima, Washington. She says growing hops in a greenhouse usually involves expensive equipment designed specifically for them.

“We’re finding that some people are trying different things, like growing in greenhouses, but that would be quite expensive,” she says. “And then people are tending to just drop out of growing hops in different regions now because there’s a capacity that you have to hit to be financially feasible, because there’s a lot of things that people aren’t considering in their budgeting process.”

When it comes to cost, Brophy and Pearson both reference cost estimates. Although the estimates are for outdoor production, Pearson says greenhouse growers could adjust by inputting their own unique costs.

Demand for dwarf

Downy mildew can affect hop foliage near the ground, so Pearson recommends that greenhouse hop growers prune toward the bottom of their plants to prevent the disease. They can also select certain varieties like Chinook, which produces more cones near the top of the plant versus the bottom.

Pearson says he is interested in working with hop breeders to breed dwarf and day-neutral hop varieties that could possibly help with some of the height and light requirements. Stelzer is also interested in dwarf varieties since leaning and lowering bines is labor-intensive in 24 Hour Hops’ 10-foot-tall greenhouse.

“Most of that [dwarf variety breeding] has come out of the U.K., and there has been some breeding for dwarf hop varieties in the Pacific Northwest to reduce labor costs of having these big, 20-foot-tall bines and specialized equipment,” Pearson says. “With that said, I have yet to get my hands on dwarf varieties. Because if they are there — and then again, I’ve seen documentation of them — they’re very coveted, and not everyone wants to share their germplasm.”

Knowing the market

One of the biggest considerations for greenhouse hop production is evaluating and meeting demand of a market that is largely already being served by producers in Washington, Oregon and Idaho. In fact, 97% of the U.S.’s hops are grown in just those three states, according to the 2017 Census of Agriculture.

When produced outdoors in the Pacific Northwest, fresh hops are only available once a year in the fall. That’s because lupulin — a compound responsible for important beer qualities such as “bittering” aromas and tastes — is only available on cones flowering outdoors in the fall, Brophy says, and cannot be replicated in greenhouses at other times.

The environment is likely responsible for lupulin production, Pearson says, but he has not seen any research that states exactly how. He and his colleagues found in their greenhouse studies that lupulin levels increased in consecutive production years but had not reached the levels of those reported for similar varieties grown in the Pacific Northwest.

Hydroponic greenhouse grower Mark Koehler, owner of Hank’s Hops in Von Ormy, Texas, aims to produce fresh hops year-round, harvesting three times a year. After two years researching and developing hops production in his greenhouse, Koehler completed his first harvest for commercial sales in the spring. He notes that his hops’ lupulin levels are high, as are the alpha acids in the lupulin glands.

“The brewers are looking for high alpha acid levels in the hops because that enables them to use less of them, and they’ll have more aromas and more flavors,” Koehler says. “The varietal that I’m growing right now — they usually average between 7 and 9% alpha acids. The ones I grew were 11.13%.”

Koehler delivered Hank’s Hops to San Antonio’s Southerleigh Fine Food and Brewery, and the operation brewed them into an all-Texas-grown-ingredient beer to serve in its taproom.

“As far as I know, this beer that’s coming out with Southerleigh is the first all-Texas-ingredient beer to be sold commercially,” Koehler says. “That’s everything from the yeast to the malt, the hops — everything came from Texas.”

For many brewers, acquiring fresh hops to brew beers locally would be preferable to having pelletized hops or dried cones shipped in from afar, as long as orders can be fulfilled and the quality is controlled, says Charles Vallhonrat, executive director of the Texas Craft Brewers Guild.

“People love to make fresh-hop beers, but they’re difficult to make,” Vallhonrat says. “You’ve got to get the hops; timing has got to work out and you’ve got to ship it and everything.”

An Orlando, Florida, company called Florida Hops breeds hops, trials varieties, grows hop plugs in a greenhouse and consults with hop growers throughout Florida. Founder Richard M. Smith says Florida hop growers, most of whom are outdoors, are garnering interest from brewers.

“We have folks from Colorado who work in a brewery like, ‘Oh man, I love the fact that I can get wet and fresh hops in Florida. I thought I wouldn’t be able to do that,’” Smith says. “But then you have folks that say, ‘I’ve never used this before and I’m hesitant to change what I’m doing.’”

A few different factors influenced Smith’s decision to start working with growers through Florida Hops, which he founded in 2016: the locavore movement, the ability to support the brewing of fresh-hop beer and the opportunity to provide hops education to a state population that is already enthusiastic about beer.

“The potential for us is to produce something local to add to the whole craft beer climate,” Smith says. “Hop yards become an attractive piece to this whole thing, so there’s that interest in there. And there’s a lot of collaboration between the brewers and the growers. They’re able to attract people into the breweries because now we have a wet-hop beer.”

Since greenhouse growers can mature hops faster indoors than outdoors, some greenhouses are growing specific varieties to fill requests from their brewer customers, Vanden Heuvel says.

“If some of these small brewpubs want to have a harvest ale and serve it in the middle of February, they can go and get these wet, fresh-picked hops and serve their harvest ale in February and have it as a mainstay at their pub,” he says.

Pearson says the type of customer will largely determine if growing niche product in a greenhouse is feasible. It could make sense for a greenhouse to start plants for hobbyist growers and brewers, and agritourism operations to finish. Growing in a greenhouse as a commercial finished grower could be more complicated.

That’s not to say that it’s impossible. Koehler, for one, has answered other growers’ questions about his process, and thinks more greenhouses will start growing hops. He has a few words of advice.

“Be ready to work, but it’s a labor of love” Koehler says. “It’s fun and it’s a very fun industry to be a part of. When you get to have a drink of that beer that you grew, it’s a cool feeling.”